Synergistc stabilizer composition for color stable pigmented thermophastic polymers in prolonged contact with water

ABSTRACT

The invention relates to synergistic stabilizer compositions comprising Hindered Amine Stabilizers (HAS), phenolic antioxidants, and, if appropriate, UV-absorbers, for pigmented thermoplastic polymers, especially for polyolefin pipes and other polyolefin molding materials, which are in prolonged contact with water. These mixtures show superior long term performance as measured by standard test methods such as color measurements.

The invention relates to synergistic stabilizer compositions comprising Hindered Amine Stabilizers (HAS), phenolic antioxidants, and, if appropriate, UV-absorbers, for color stable pigmented thermoplastic polymers, especially for polyolefin pipes and other polyolefin molding materials, which are in prolonged contact with water.

Pigmented plastic articles like blue-pigmented PE-HD water pipes used under long-term conditions in aqueous surroundings particularly at elevated temperatures suffer according to common observations by undesired changes of color. Furthermore the suitable support to keep initial aspect properties is often necessary according to technical requirements especially for articles such as water pipes and polymer-based equipment in general which is used under permanent water extractive conditions e.g. dish washers, washing machines and other kitchen articles.

The extent of this effect can be measured using parameters like the b*-value which reflects a value of the space coordinates on the yellow-blue-axis given by the so called CIELAB-system to define color and color valences of test pieces [Reference: H. G. Völz, “Industrielle Farbprüfung”; VCH-publishing comp., Weinheim, N.Y., Basel, Cambridge, 1990, pp. 23].

Besides the maintenance of their optical and also mechanical properties the repression of detrimental thermally and photochemically initiated degradation processes of the polymer is an important goal using the right stabilizer or stabilizer combination.

So far it was not sufficiently possible to influence efficiently those drawbacks by means of an appropriate stabilizer system.

Surprisingly it was found that combinations of special sterically hindered phenols and phenol-combinations guarantee in pigmented articles like blue-pigmented PE-HD water pipes an unusual color stability besides other properties if stored even at elevated temperatures under long term conditions. This efficiency is even more pronounced if those phenols and phenol-combinations are applied together with stabilizers based on sterically hindered piperidine compounds (HAS) technically known as effective light- and heatstabilizers.

Also multiple combinations of the special phenol-component with conventional sterically hindered phenols and certain sterically hindered amines show superior effects. The instant stabilizer combinations offer surprisingly the possibility to out-perform the state of the art.

Object of the instant invention are stabilizer compositions for pigmented thermoplastic polymers comprising

-   -   a) at least one sterically hindered amine, one of which must be         the polymer of epichlorohydrin and 2,2,4,4-tetramethyl-7-oxa-3,         20-diaza-20-(2,3-epoxi-propyl)-dispiro-[5.1.11.2]-heneicosane-21-one         (LS 1), the others being         poly-{[6[1,1,3,3-tetramethylbutyl)-imino]-1,3,5-triazine-2,4-diyl][2-(2,2,6,6-tetramethyl-piperidyl)-amino]-hexamethylene-[4-(2,2,6,6-tetramethyl-piperidyl)-imino]}         (LS 2) or         poly-(N-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxy-piperidyl-succinate)         (LS 3),         and     -   b) at least the phenolic antioxidants         bis-[3,3-bis-(4′-hydroxy-3′-tert.butylphenyl)-butanoic         acid]-glycolester (AO 1) and         tetrakismethylene(3,5-di-tert.butyl-4-hydroxyphenyl)-hydrocinnamate         (AO 2),         wherein the overall weight ratio of component(s) a) to the         overall weight ratio of component(s) b) is from 10:1 to 1:5.

Preferred are stabilizer compositions wherein component b) is selected from the compounds (AO 1) to (AO 8):

-   bis-[3,3-bis-(4′-hydroxy-3′-tert.butylphenyl)-butanoic     acid]-glycolester (AO 1), -   tetrakismethylene(3,5-di-tert.butyl-4-hydroxyphenyl)-hydrocinnamate     (AO 2), -   octadecyl-3-(3,5-di-tert.butyl-4-hydroxyphenyl)-propionate (AO 3), -   4,4′,4″-[(2,4,6-trimethyl-1,3,5-benzenetriyl)-tris(methylene)]-tris[2,6-bis(1,1-di-methylethyl)-phenol]     (AO 4), -   1,3,5-triazine-2,4,6(1H,3H,5H)-trione,     1,3,5-tris[[4-(1,1-dimethylethyl)-3-hydroxy-2,6-dimethylphenyl]methyl]     (AO 5), -   phenol,     4,4′,4″-(1-methyl-1-propanyl-3-ylidene)tris[2-(1,1-dimethylethyl)-5-methyl     (AO 6), -   phenol,     2,6-bis[[3-(1,1-dimethylethyl)-2-hydroxy-5-methylphenyl]octahydro-4,7-methano-1H-indenyl]-4-methyl     (AO 7), or -   benzenepropanoic acid, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-,     2,4,8,10-tetra-oxa-spiro[5.5]undecane-3,9-diylbis(2,2-dimethyl-2,1-ethanediyl)     ester (AO 8).

Preferred are stabilizer compositions wherein component b) is is a mixture of compound (AO 1) and (AO 2) in a weight ratio of 5:1 to 1:5, more preferably of 2:1 to 1:2.

Very good stabilizing properties are also achieved with stabilizer compositions wherein an additional UV-absorber as further component c) is methanone, [2-hydroxy-4-(octyl-oxy)phenyl]phenyl (UV 1) or phenol, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethyl-ethyl)-4-methyl (UV 2) or a 2-hydroxybenzophenone, a 2-(2-hydroxyphenyl)-benzo-triazole, a 2-(2-hydroxyphenyl)-1,3,5-benzotriazine, an oxanilide, a cinnamate or a salicylate, and wherein the weight ratio of component(s) a): component(s) b): component(s) c) is from 5:1:1 to 1:5:5.

The compounds (LS 1) to (LS 3), (AO 1) to (AO 8), (UV 1) and (UV 2) are commercially available products of the following chemical structure, as far as known:

Compound (LS 1):

-   polymer of epichlorohydrin and 2,2,4,4-tetramethyl-7-oxa-3,     20-diaza-20-(2,3-epoxipropyl)-dispiro-[5.1.11.2]-heneicosane-21-one;

A further object of the instant invention is a method of use of said stabilizer compositions for the stabilization of pigmented thermoplastic polymers, especially polyolefins, which are in prolonged contact with extracting media like water, in concentrations of 0.001% to 2.000%, preferably 0.020% to 0.20% by weight, based on the polymer.

Another object of the instant invention is a process of stabilizing pigmented thermo-plastic polymers, especially polyolefins, which are in prolonged contact with extracting media like water, by incorporating 0.001% to 2.000%, preferably 0.020% to 0.20% by weight, based on the polymer, of said stabilizer compositions.

Suitable thermoplastic polymers to be stabilized according to the instant invention are for example the following ones:

-   1. Polymers of monoolefins and diolefins, for example polypropylene,     polyiso-butylene, polybut-1-ene, poly-4-methylpent-1-ene,     polyisoprene or polybutadiene, as well as polymers of cycloolefins,     for example of cyclopentene or norbornene; furthermore polyethylene     (which optionally can be crosslinked); for example, high density     polyethylene (HDPE), polyethylene of high density and high molar     mass (HDPE-HMW), polyethylene of high density and ultrahigh molar     mass (HDPE-UHMW), medium density polyethylene (HMDPE), low density     polyethylene (LDPE), linear low density polyethylene (LLDPE),     branched low density poly-ethylene (BLDPE).     -   Polyolefins, i.e. polymers of monoolefins exemplified in the         preceding paragraph, in particular polyethylene and         polypropylene, can be prepared by various, and especially by the         following, methods:         -   a) free-radical polymerization (normally under high pressure             and at elevated temperature)         -   b) catalytic polymerization using a catalyst that normally             contains one or more metals of group IVb, Vb, VIb or VIII of             the Periodic Table. These metals usually have one or more             ligands, such as oxides, halides, alcoholates, esters,             ethers, amines, alkyls, alkenyls and/or aryls that may be             either π- or σ-coordinated. These metal complexes may be in             the free form or fixed on substrates, for example on             activated magnesium chloride, titanium(III) chloride,             alumina or silicon oxide. These catalysts may be soluble or             insoluble in the polymerization medium. The catalysts can be             active as such in the polymerization or further activators             may be used, for example metal alkyls, metal hydrides, metal             alkyl halides, metal alkyl oxides or metal alkyloxanes, the             metals being elements of groups Ia, IIa and/or IIIa of the             Periodic Table. The activators may be modified, for example,             with further ester, ether, amine or silyl ether groups.             These catalyst systems are usually termed Phillips, Standard             Oil Indiana, Ziegler (-Natta), TNZ (DuPont), metallocene or             single site catalysts (SSC). -   2. Mixtures of the polymers mentioned under 1), for example mixtures     of polypropylene with polyisobutylene, polyethylene with     polyisobutylene, polypropylene with polyethylene (for example     PP/HDPE/LDPE) and mixtures of different types of polyethylene (for     example LDPE/HDPE) with one another. -   3. Copolymers of monoolefins and diolefins with each other or with     other vinyl monomers, for example ethylene-propylene copolymers,     linear low density polyethylene (LLDPE) and mixtures thereof with     low density polyethylene (LDPE), propylene-but-1-ene copolymers,     propylene-isobutylene copolymers, ethylene-but-1-ene copolymers,     ethylene-hexene copolymers, ethylene-methyl-pentene copolymers,     ethylene-heptene copolymers, ethylene-octene copolymers,     propylene-butadiene copolymers, isobutylene-isoprene copolymers,     ethylene-alkyl acrylate copolymers, ethylene-alkyl methacrylate     copolymers, ethylene-vinyl acetate copolymers and their copolymers     with carbon monoxide or ethylene-acrylic acid copolymers and their     salts (ionomers) as well as terpolymers of ethylene with propylene     and a diene such as hexadiene, dicyclopentadiene or     ethylidene-norbornene; and mixtures of such copolymers with one     another and with polymers mentioned under 1), for example     polypropylene-ethylene-propylene copolymers, LDPE-ethylene-vinyl     acetate copolymers, LDPE-ethylene-acrylic acid copolymers,     LLDPE-ethylene-vinyl acetate copolymers, LLDPE-ethylene-acrylic acid     copolymers and alternating or random polyalkylene-carbon monoxide     copolymers and mixtures thereof with other polymers, for example     polyamides. -   4. Hydrocarbon resins (for example C₅-C₉) including hydrogenated     modifications thereof (e.g. tackifier resins) and mixtures of     polyalkylenes and starch. -   5. Polystyrene, poly(p-methylstyrene), poly(α-methylstyrene). -   6. Copolymers of styrene or α-methylstyrene with dienes or acrylic     derivatives, for example styrene-butadiene, styrene-acrylonitrile,     styrene-alkyl methacrylate, styrene-butadiene-alkyl acrylate,     styrene-butadiene-alkyl methacrylate, styrene-maleic anhydride,     styrene-acrylonitrile-methacrylate; mixtures of high impact strength     of styrene copolymers and another polymer, for example a     polyacrylate, a diene polymer or an ethylene-propylene-diene     terpolymer; and block copolymers of styrene, such as     styrene-butadiene-styrene, styrene-isoprene-styrene,     styrene-ethylene/butylene-styrene or     styrene-ethylene/propylene-styrene. -   7. Graft copolymers of styrene or α-methylstyrene, for example     styrene on polybutadiene, styrene on polybutadiene-styrene or     polybutadiene-acrylonitrile copolymers, styrene and acrylonitrile     (or methacrylonitrile) on polybutadiene; styrene, acrylonitrile and     methyl methacrylate on polybutadiene; styrene and maleic anhydride     on polybutadiene; styrene, acrylonitrile and maleic anhydride or     maleimide on polybutadiene; styrene and maleimide on polybutadiene;     styrene and alkyl acrylates or alkyl methacrylates on polybutadiene,     styrene and acrylonitrile on ethylene-propylene-diene terpolymers,     styrene and acrylonitrile on polyalkyl acrylates or polyalkyl     methacrylates, styrene and acrylonitrile on acrylate-butadiene     copolymers, as well as mixtures thereof with the copolymers     mentioned under 6), for example the copolymer mixtures known as ABS,     MBS, ASA or AES polymers. -   8. Halogen-containing polymers, such as polychloroprene, chlorinated     rubber, chlorinated and brominated copolymer of isobutylene-isoprene     (halobutyl rubber), chlorinated or sulfochlorinated polyethylene,     copolymers of ethylene and chlorinated ethylene, epichlorohydrin     homo- and copolymers, especially polymers of halogen-containing     vinyl compounds, for example polyvinyl chloride, polyvinylidene     chloride, polyvinyl fluoride, polyvinylidene fluoride; as well as     copolymers thereof such as vinyl chloride-vinylidene chloride, vinyl     chloride-vinyl acetate or vinylidene chloride-vinyl acetate. -   9. Polymers derived from α,β-unsaturated acids and derivatives     thereof, such as polyacrylates and polymethacrylates,     polyacrylonitriles, polyacrylamides and polymethyl methacrylates     impact-modified with butyl acrylate. -   10. Copolymers of the monomers mentioned under 9) with each other or     with other unsaturated monomers, for example acrylonitrile-butadiene     copolymers, acrylonitrile-alkyl acrylate copolymers,     acrylonitrile-alkoxyalkyl acrylate copolymers, acrylonitrile-vinyl     halide copolymers or acrylonitrile-alkyl methacrylate-butadiene     terpolymers. -   11. Polymers derived from unsaturated alcohols and amines or the     acyl derivatives or acetals thereof, such as polyvinyl alcohol,     polyvinyl acetate, polyvinyl stearate, polyvinyl benzoate, polyvinyl     maleate, polyvinyl butyral, polyallyl phthalate or polyallyl     melamine; as well as their copolymers with olefins mentioned in     section 1. -   12. Homopolymers and copolymers of cyclic ethers, such as     polyalkylene glycols, polyethylene oxide, polypropylene oxide or     copolymers thereof with bisglycidyl ethers. -   13. Polyacetals such as polyoxymethylene and those polyoxymethylenes     which contain comonomers, for example ethylene oxide; polyacetals     modified with thermoplastic polyurethanes, acrylates or MBS. -   14. Polyphenylene oxides and sulfides, and mixtures thereof with     styrene polymers or polyamides. -   15. Polyurethanes derived from hydroxyl-terminated polyethers,     polyesters and polybutadienes on the one hand and aliphatic or     aromatic polyisocyanates on the other, as well as precursors     thereof. -   16. Polyamides and copolyamides derived from diamines and     dicarboxylic acids and/or from aminocarboxylic acids or the     corresponding lactams, such as polyamide 4, 6, 6/6, 6/10, 6/9, 6/12,     4/6, 12/12, 11 and 12, aromatic polyamides starting from m-xylene,     diamine and adipic acid; polyamides prepared from     hexamethylenediamine and isophthalic and/or terephthalic acid and     with or without an elastomer as modifier, for example     poly-2,4,4-trimethylhexamethylene terephthalamide or     poly-m-phenylene isophthalamide. Block copolymers of the     aforementioned polyamides with polyolefins, olefin copolymers,     ionomers or chemically bonded or grafted elastomers; or with     polyethers, e.g. with polyethylene glycol, polypropylene glycol or     polytetramethylene glycol. As well as polyamides or copolyamides     modified with EPDM or ABS; and polyamides condensed during     processing (RIM polyamide systems). -   17. Polyureas, polyimides, polyamide-imides, polyether imides,     polyester amides, polyhydantoins and polybenzimidazoles. -   18. Polyesters derived from dicarboxylic acids and dialcohols and/or     from hydroxy-carboxylic acids or the corresponding lactones, such as     polyethylene terephthalate, polybutylene terephthalate,     poly-1,4-dimethylolcyclohexane terephthalate, polyhydroxybenzoates,     as well as block polyether esters derived from hydroxyl-terminated     polyethers; and also polyesters modified with polycarbonates or MBS. -   19. Polycarbonates and polyester carbonates. -   20. Polysulfones, polyether sulfones and polyether ketones. -   21. Crosslinked polymers derived from aldehydes on the one hand and     phenols, urea or melamine on the other hand, such as     phenol/formaldehyde resins, urea/formaldehyde resins and     melamine/formaldehyde resins. -   22. Drying and non-drying alkyd resins. -   23. Unsaturated polyester resins derived from copolyesters of     saturated and unsaturated dicarboxylic acids with polyhydric     alcohols and vinyl compounds as crosslinking agents, and also     halogen-containing modifications thereof of low flammability. -   24. Crosslinkable acrylic resins derived from substituted acrylates,     for example from epoxy acrylates, urethane acrylates or polyester     acrylates. -   25. Alkyd resins, polyester resins and acrylic resins crosslinked     with melamine resins, urea resins, isocyanates, isocyanurates,     polyisocyanates or epoxy resins. -   26. Crosslinked epoxy resins derived from aliphatic, cycloaliphatic,     heterocyclic or aromatic glycidyl compounds, examples being products     of bisphenol A diglycidyl ethers, bisphenol F diglycidyl ethers,     which are crosslinked by means of customary hardeners, such as     anhydrides or amines, for example, with or without accelerators. -   27. Natural polymers such as cellulose, natural rubber, gelatin and     derivatives thereof which have been chemically modified in a     polymer-homologous manner, for example cellulose acetates, cellulose     propionates and cellulose butyrates, or the cellulose ethers such as     methyl cellulose; as well as rosins and derivatives. -   28. Mixtures (polyblends) of the aforementioned polymers, for     example PP/EPDM, polyamide/EPDM or ABS, PVC/EVA, PVC/ABS, PVC/MBS,     PC/ABS, PBTP/ABS, PC/ASA, PC/PBT, PVC/CPE, PVC/acrylates,     POM/thermoplastic PUR, PC/thermoplastic PUR, POM/acrylate, POM/MBS,     PPO/MBS, PPO/HIPS, PPO/PA 6.6 and copolymers, PA/HDPE, PA/PP,     PA/PPO, PBT/ABS or PBT/PET/PC. -   29. Natural and synthetic organic substances which constitute pure     monomeric compounds or mixtures thereof, examples being mineral     oils, animal or vegetable fats, oils and waxes, or oils, waxes and     fats based on synthetic esters (e.g. phthalates, adipates,     phosphates or trimellitates), and also blends of synthetic esters     with mineral oils in any desired proportion by weight, as are     employed, for example, as spin finishes, and aqueous emulsions     thereof. -   30. Aqueous emulsions of natural or synthetic rubbers, such as     natural rubber latex or latices of carboxylated styrene-butadiene     copolymers.

The stabilizer compositions of the instant invention or the thermoplastic polymers to be stabilized may if desired also comprise further additives, examples being antioxidants, light stabilizers, metal deactivators, antistatic agents, flame retardants, lubricants, nucleating agents, acid scavengers (basic costabilizers), pigments and fillers. Examples of suitable additives which can additionally be employed in combination are compounds as set out below:

1. Antioxidants

-   1.1 Alkylated monophenols, for example     2,6-di-tert-butyl-4-methylphenol, 2-butyl-4,6-dimethylphenol,     2,6-di-tert-butyl-4-ethylphenol, 2,6-di-tert-butyl-4-n-butylphenol,     2,6-di-tert-butyl-4-isobutylphenol,     2,6-dicyclopentyl-4-methylphenol,     2-(α-methyl-cyclohexyl)-4,6-dimethylphenol,     2,6-dioctadecyl-4-methylphenol, 2,4,6-tricyclo-hexylphenol,     2,6-di-tert-butyl-4-methoxymethylphenol, linear or     sidechain-branched nonylphenols, such as     2,6-di-nonyl-4-methylphenol,     2,4-dimethyl-6-(1-methylundec-1′-yl)-phenol,     2,4-dimethyl-6-(1′-methylheptadec-1′-yl)-phenol,     2,4-dimethyl-6-(1′-methyltridec-1′-yl)phenol and mixtures thereof. -   1.2 Alkylthiomethylphenols, for example     2,4-dioctylthiomethyl-6-tert-butylphenol,     2,4-dioctylthiomethyl-6-methylphenol,     2,4-dioctylthiomethyl-6-ethylphenol,     2,6-di-dodecylthiomethyl-4-nonylphenol. -   1.3 Hydroquinones and alkylated hydroquinones, for example     2,6-di-tert-butyl-4-methoxyphenol, 2,5-di-tert-butylhydroquinone,     2,5-di-tert-amylhydroquinone, 2,6-diphenyl-4-octadecyloxyphenol,     2,6-di-tert-butylhydroquinone, 2,5-di-tert-butyl-4-hydroxyanisole,     3,5-di-tert-butyl-4-hydroxyanisole,     3,5-di-tert-butyl-4-hydroxyphenyl stearate,     bis(3,5-di-tert-butyl-4-hydroxyphenyl) adipate. -   1.4 Hydroxylated thiodiphenyl ethers, for example     2,2′-thiobis(6-tert-butyl-4-methylphenol),     2,2′-thiobis(4-octylphenol),     4,4′-thiobis(6-tert-butyl-3-methylphenol),     4,4′-thiobis(6-tert-butyl-2-methylphenol),     4,4′-thiobis(3,6-di-sec-amylphenol),     4,4′-bis-(2,6-dimethyl-4-hydroxyphenyl) disulfide. -   1.5 Alkylidenebisphenols, for example     2,2′-methylenebis(6-tert-butyl-4-methylphenol),     2,2′-methylenebis(6-tert-butyl-4-ethylphenol),     2,2′-methylenebis[4-methyl-6-(α-methylcyclohexyl)phenol],     2,2′-methylenebis(4-methyl-6-cyclo-hexylphenol),     2,2′-methylenebis(6-nonyl-4-methylphenol),     2,2′-methylenebis(4,6-di-tert-butylphenol),     2,2′-ethylidenebis(4,6-di-tert-butylphenol),     2,2′-ethylidene-bis(6-tert-butyl-4-isobutylphenol),     2,2′-methylenebis[6-(α-methylbenzyl)-4-nonylphenol],     2,2′-methylenebis[6-(α,α-dimethylbenzyl)-4-nonylphenol],     4,4′-methylenebis(2,6-di-tert-butylphenol),     4,4′-methylenebis(6-tert-butyl-2-methylphenol),     1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,     2,6-bis(3-tert-butyl-5-methyl-2-hydroxybenzyl)-4-methylphenol,     1,1,3-tris(5-tert-butyl-4-hydroxy-2-methylphenyl)butane,     1,1-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-3-n-dode-cylmercaptobutane,     bis(3-tert-butyl-4-hydroxy-5-methylphenyl)-dicyclopentadiene,     bis[2-(3′-tert-butyl-2′-hydroxy-5′-methylbenzyl)-6-tert-butyl-4-methylphenyl]terephthalate,     1,1-bis(3,5-dimethyl-2-hydroxyphenyl)butane,     2,2-bis(3,5-di-tert-butyl-4-hydroxyphenyl)propane,     2,2-bis(5-tert-butyl-4-hydroxy-2-methylphenyl)-4-n-dodecylmercaptobutane,     1,1,5,5-tetra-(5-tert-butyl-4-hydroxy-2-methylphenyl)-pentane,     ethylene glycol     bis[3,3-bis(3′-tert-butyl-4′-hydroxyphenyl)butyrate]. -   1.6 O-, N- and S-benzyl compounds, for example     3,5,3′,5′-tetra-tert-butyl-4,4′-dihydroxydibenzyl ether, octadecyl     4-hydroxy-3,5-dimethylbenzylmercaptoacetate,     tris(3,5-di-tert-butyl-4-hydroxybenzyl)amine,     bis(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)dithioterephthalate,     bis(3,5-di-tert-butyl-4-hydroxybenzyl)sulfide, isooctyl     3,5-di-tert-butyl-4-hydroxybenzylmercaptoacetate, tridecyl     4-hydroxy-3,5-di-tert-butylbenzylmercaptoacetate. -   1.7 Hydroxybenzylated malonates, for example dioctadecyl     2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl)malonate, dioctadecyl     2-(3-tert-butyl-4-hydroxy-5-methylbenzyl)malonate,     didodecyl-mercaptoethyl-2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate,     di-[4-(1,1,3,3-tetramethylbutyl)phenyl]2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate. -   1.8 Aromatic hydroxybenzyl compounds, for example     1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,     1,4-bis(3,5-di-tert-butyl-4-hydroxybenzyl)-2,3,5,6-tetramethylbenzene,     2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)phenol. -   1.9 Triazine compounds, for example     2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,     2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,     2-octylmercapto-4,6-bis(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,3,5-triazine,     2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenoxy)-1,2,3-triazine,     1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl) isocyanurate,     1,3,5-tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurat,     2,4,6-tris(3,5-di-tert-butyl-4-hydroxyphenylethyl)-1,3,5-triazine,     1,3,5-tris(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexahydro-1,3,5-triazine,     1,3,5-tris(3,5-dicyclohexyl-4-hydroxybenzyl)isocyanurate. -   1.10 Benzylphosphonates, for example dimethyl     2,5-di-tert-butyl-4-hydroxybenzylphosphonate,     diethyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,     dioctadecyl-3,5-di-tert-butyl-4-hydroxybenzylphosphonate,     dioctadecyl-5-tert-butyl-4-hydroxy-3-methylbenzylphosphonate, the     Ca-salt of the monoethyl ester of     3,5-di-tert-butyl-4-hydroxybenzylphosphonic acid. -   1.11 Acylaminophenols, for example 4-hydroxylauranilide,     4-hydroxystearanilide, octyl     N-(3,5-di-tert-butyl-4-hydroxyphenyl)carbamate. -   1.12 Esters of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid     with mono- or polyhydric alcohols, e.g. with methanol, ethanol,     n-octanol, isooctanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,     ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene     glycol, diethylene glycol, triethylene glycol, pentaerythritol,     tris(hydroxyethyl) isocyanurate, N,N′-bis(hydroxyethyl)oxalamide,     3-thia-undecanol, 3-thia-pentadecanol, trimethylhexanediol,     trimethylolpropane,     4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. -   1.13 Esters of β-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic     acid with mono- or polyhydric alcohols, e.g. with methanol, ethanol,     n-octanol, isooctanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,     ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene     glycol, diethylene glycol, triethylene glycol, pentaerythritol,     tris(hydroxyethyl) isocyanurate, N,N′-bis(hydroxyethyl)oxalamide,     3-thia-undecanol, 3-thiapentadecanol, trimethylhexanediol,     trimethylolpropane,     4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. -   1.14 Esters of β-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid     with mono- or polyhydric alcohols, e.g. with methanol, ethanol,     n-octanol, isooctanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,     ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene     glycol, diethylene glycol, triethylene glycol, pentaerythritol,     tris(hydroxyethyl) isocyanurate, N,N′-bis(hydroxyethyl)oxalamide,     3-thia-undecanol, 3-thia-pentadecanol, trimethylhexanediol,     trimethylolpropane,     4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. -   1.15 Esters of 3,5-di-tert-butyl-4-hydroxyphenylacetic acid with     mono- or polyhydric alcohols, e.g. with methanol, ethanol,     n-octanol, isooctanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,     ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene     glycol, diethylene glycol, triethylene glycol, pentaerythritol,     tris-(hydroxyethyl) isocyanurate, N,N′-bis-(hydroxyethyl)oxalamide,     3-thiaundecanol, 3-thiapentadecanol, trimethylhexanediol,     trimethylolpropane,     4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. -   1.16 Esters of 3,3-bis(3′tert-butyl-4′-hydroxyphenyl)butyric acid     with mono- or polyhydric alcohols, e.g. with methanol, ethanol,     n-octanol, isooctanol, octadecanol, 1,6-hexanediol, 1,9-nonanediol,     ethylene glycol, 1,2-propanediol, neopentyl glycol, thiodiethylene     glycol, diethylene glycol, triethylene glycol, pentaerythritol,     tris(hydroxyethyl) isocyanurate, N,N′-bis-(hydroxyethyl)oxalamide,     3-thia-undecanol, 3-thiapentadecanol, trimethylhexanediol,     trimethylolpropane,     4-hydroxymethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane. -   1.17 Amides of β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid,     e.g.     N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hexamethylenediamine,     N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)trimethylenediamine,     N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine. -   1.18 Tocopherol, such as α-tocopherol, β-tocopherol, γ-tocopherol,     δ-tocopherol and mixtures thereof (vitamin E). -   1.19 Ascorbic acid (vitamin C). -   1.20 Amine antioxidants, for example     N,N′-diisopropyl-p-phenylenediamine,     N,N′di-sec-butyl-p-phenylenediamine,     N,N′-bis(1,4-dimethylpentyl)-p-phenylenediamine,     N,N′-bis(1-ethyl-3-methylpentyl)-p-phenylenediamine, N,     N′-bis(1-methylheptyl)-p-phenylenediamine,     N,N′-dicyclohexyl-p-phenylenediamine, N,     N′-diphenyl-p-phenylenediamine,     N,N′-di(naphthyl-2-)-p-phenylenediamine,     N-isopropyl-N′-phenyl-p-phenylenediamine,     N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine,     N-(1-methylheptyl)-N′-phenyl-p-phenylenediamine,     N-cyclohexyl-N′-phenyl-p-phenylenediamine,     4-(-toluenesulfonamido)diphenylamine,     N,N′-di-methyl-N,N′-di-sec-butyl-p-phenylenediamine, diphenylamine,     N-allyldiphenylamine, 4-isopropoxydiphenylamine,     N-phenyl-1-naphthylamine, N-(4-tert-octylphenyl)-1-naphthylamine,     N-phenyl-2-naphthylamine, octylated diphenylamine, e.g.     p,p′-di-tert-octyldiphenylamine, 4-n-butylaminophenol,     4-butyrylaminophenol, 4-nonanoylaminophenol,     4-dodecanoylaminophenol, 4-octadecanoylaminophenol,     di(4-methoxyphenyl)amine,     2,6-di-tert-butyl-4-dimethylaminomethylphenol,     2,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylmethane, N, N,N′,     N′-tetramethyl-4,4′-diaminodiphenylmethane,     1,2-di-[(2-methylphenyl)amino]ethane, 1,2-di-(phenylamino)propane,     (o-tolyl)biguanide, di[4-(1′,3′-dimethylbutyl)-phenyl]amine,     tert-octylated N-phenyl-1-naphthylamine, mixture of mono- and     dialkylated tert-butyl/tert-octyldiphenylamines, mixture of mono-     and dialkylated nonyldiphenylamines, mixture of mono- and     dialkylated dodecyldiphenylamines, mixture of mono- and dialkylated     isopropyl/isohexyl-diphenylamines, mixture of mono- and dialkylated     tert-butyldiphenylamines,     2,3-dihydro-3,3-dimethyl-4H-1,4-benzothiazine, phenothiazine,     mixture of mono- and dialkylated     tert-butyl/tert-octyl-phenothiazines, mixture of mono- and     dialkylated tert-octylphenothiazines, N-allylphenothiazine, N,     N,N′,N′-tetraphenyl-1,4-diaminobut-2-ene,     N,N-bis-(2,2,6,6-tetramethylpiperidine-4-yl)hexamethylenediamine,     bis(2,2,6,6-tetramethylpiperidine-4-yl)sebacate,     2,2,6,6-tetramethylpiperidin-4-one,     2,2,6,6-tetramethylpiperidine-4-ol.

2. UV Absorbers and Light Stabilizers

-   2.1 2-(2′-Hydroxyphenyl)benzotriazoles, for example     2-(2′-hydroxy-5′-methylphenyl)benzotriazole,     2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)benzotriazole,     2-(5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,     2-[2′-hydroxy-5′-(1,1,3,3-tetramethylbutyl)phenyl]benzotriazole,     2-(3′,5′-di-tert-butyl-2′-hydroxyphenyl)-5-chlorobenzotriazole,     2-(3′-tert-butyl-2′-hydroxy-5′-methylphenyl)-5-chlorobenzotriazole,     2-(3′-sec-butyl-5′-tert-butyl-2′-hydroxyphenyl)benzotriazole,     2-(2′-hydroxy-4′-octoxyphenyl)benzotriazole,     2-(3′,5′-di-tert-amyl-2′-hydroxyphenyl)benzotriazole,     2-(3′,5′-bis-(α,α-dimethylbenzyl)-2′-hydroxyphenyl)benzotriazole, a     mixture of     2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)-5-chlorobenzotriazole     2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)-5-chlorobenzotriazole,     2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)-5-chlorobenzotriazole,     2-(3′-tert-butyl-2′-hydroxy-5′-(2-methoxycarbonylethyl)phenyl)benzotriazole,     2-(3′-tert-butyl-2′-hydroxy-5′-(2-octyloxycarbonylethyl)phenyl)benzotriazole,     2-(3′-tert-butyl-5′-[2-(2-ethylhexyloxy)carbonylethyl]-2′-hydroxyphenyl)benzotriazole,     2-(3′-dodecyl-2′-hydroxy-5′-methylphenyl)benzotriazole, and     2-(3′-tert-butyl-2′-hydroxy-5′-(2-isooctyloxycarbonylethyl)phenylbenzotriazole,     2,2′-methylenebis[4-(1,1,3,3-tetramethylbutyl)-6-benzotriazol-2-ylphenol];     the transesterification product of     2-[3′-tert.-butyl-5′-(2-methoxycarbonylethyl)-2′-hydroxyphenyl]benzotriazole     with polyethylene glycol 300; [R—CH₂CH₂—COO(CH₂)₃]₂ where     R=3′-tert-butyl-4′-hydroxy-5′-2H-benzotriazol-2-yl-phenyl. -   2.2 2-Hydroxybenzophenones, for example the 4-hydroxy, 4-methoxy,     4-octoxy, 4-decyloxy, 4-dodecyloxy, 4-benzyloxy, 4,2′,4′-trihydroxy     and 2′-hydroxy-4,4′-dimethoxy derivative. -   2.3 Esters of substituted or unsubstituted benzoic acids, for     example 4-tert-butylphenyl salicylate, phenyl salicylate,     octylphenyl salicylate, dibenzoylresorcinol,     bis(4-tert-butylbenzoyl)resorcinol, benzoylresorcinol,     2,4-di-tert-butylphenyl 3,5-di-tert-butyl-4-hydroxybenzoate,     hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, octadecyl     3,5-di-tert-butyl-4-hydroxybenzoate,     2-methyl-4,6-di-tert-butylphenyl     3,5-di-tert-butyl-4-hydroxybenzoate. -   2.4 Acrylates, for example ethyl α-cyano-β,β-diphenylacrylate or     isooctyl α-cyano-β,β-diphenylacrylate, methyl     α-carbomethoxycinnamate, methyl α-cyano-β-methyl-p-methoxycinnamate     or butyl α-cyano-β-methyl-p-methoxycinnamate, methyl     α-carbomethoxy-p-methoxycinnamate and     N-(β-carbomethoxy-β-cyano-vinyl)-2-methylindoline. -   2.5 Nickel compounds, for example nickel complexes of     2,2′-thio-bis-[4-(1,1,3,3-tetramethylbutyl)phenol], such as the 1:1     or 1:2 complex, with or without additional ligands such as     n-butylamine, triethanolamine or N-cyclohexyldiethanolamine, nickel     dibutyldithiocarbamate, nickel salts of monoalkyl esters, such as of     the methyl or ethyl ester, of     4-hydroxy-3,5-di-tert-butylbenzylphosphonic acid, nickel complexes     of ketoximes, e.g. of 2-hydroxy-4-methylphenyl undecyl ketoxime,     nickel complexes of 1-phenyl-4-lauroyl-5-hydroxypyrazole, with or     without additional ligands. -   2.6 Sterically hindered amines, for example     bis(2,2,6,6-tetramethylpiperidine-4-yl) sebacate,     bis(2,2,6,6-tetramethylpiperidine-4-yl) glutarate,     bis(2,2,6,6-tetramethylpiperidine-4-yl)succinate,     bis(1,2,2,6,6-pentamethylpiperidine-4-yl)sebacate,     bis(1,2,2,6,6-pentamethylpiperidine-4-yl) glutarate,     2,2,6,6-tetramethylpiperidyl behenate,     1,2,2,6,6-pentamethylpiperidyl-behenate, the condensate of     1-hydroxyethyl-2,2,6,6-tetramethyl-4-hydroxypiperidine and succinic     acid, the condensate of     N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)hexamethylendiamine and     4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine,     tris-(2,2,6,6-tetramethyl-4-piperidyl) nitrilo-triacetate,     tetrakis(2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butantetraoate,     1,1′-(1,2-ethanediyl)-bis-(3,3,5,5-tetramethylpiperazinone),     4-benzoyl-2,2,6,6-tetramethylpiperidine,     4-stearyloxy-2,2,6,6-tetramethylpiperidine,     4-stearoyloxy-2,2,6,6-tetramethylpiperidine,     4-stearyloxy-1,2,2,6,6-pentamethylpiperidine,     4-stearoyloxy-1,2,2,6,6-pentamethylpiperidine,     bis(1,2,2,6,6-pentamethylpiperidyl)     2-n-butyl-2-(2-hydroxy-3,5-di-tert-butylbenzyl)malonate,     bis(1,2,2,6,6-pentamethylpiperidyl)     2-n-butyl-2-(4-hydroxy-3,5-di-tert-butylbenzyl)malonate,     3-n-octyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]     decane-2,4-dione, bis(1-octyloxy-2,2,6,6-tetramethylpiperidyl)     sebacate, bis-(1-octyloxy-2,2,6,6-tetramethylpiperidyl)succinate,     the condensate of     N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and     4-morpholino-2,6-dichloro-1,3,5-triazine, the condensate of     N,N′-bis(2,2,6,6-tetramethyl-4-piperidyl)hexamethylenediamine and     4-cyclohexylamino-2,6-dichloro-1,3,5-triazine, the condensate of     2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine     and 1,2-bis-(3-aminopropylamino)ethane, the condensate of     2-chloro-4,6-di-(4-methoxypropylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine     and 1,2-bis-(3-aminopropylamino)ethane, the condensate of     2-chloro-4,6-di-(4-methoxypropylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine     and 1,2-bis-(3-aminopropylamino)ethane, the condensate of     2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine     and 1,2-bis-(3-aminopropylamino)-ethane, reaction products of     2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine     with mono- or polyfunctional amines, where between one and all the     active hydrogen atoms on the amine are replaced, such as with     ethylenediamine, diethylenetriamine, triethylenetetramine,     hexamethylenediamine, 1,2-bis-(3-aminopropylamino)ethane, reaction     products of     2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine     with mono- or polyfunctional amines, where between one and all the     active hydrogen atoms on the amine are replaced, such as with     ethylenediamine, diethylenetriamine, triethylenetetramine,     hexamethylenediamine, 1,2-bis(3-aminopropylamino)ethane, reaction     products of     2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine     and 4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine with mono- or     polyfunctional amines, where between one and all the active hydrogen     atoms on the amine are replaced, such as with ethylenediamine,     diethylenetriamine, triethylenetetramine, hexamethylenediamine,     1,2-bis(3-aminopropylamino)ethane, reaction products of     2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine     and 4-tert-octylamino-2,6-dichloro-1,3,5-s-triazine with mono- or     polyfunctional amines, where between one and all the active hydrogen     atoms on the amine are replaced, such as with ethylenediamine,     diethylenetriamine, triethylenetetramine, hexamethylenediamine,     1,2-bis-(3-aminopropyl-amino)ethane, reaction products of     2-chloro-4,6-di-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-1,3,5-triazine     and     4-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-2,6-dichloro-1,3,5-s-triazine     with mono- or polyfunctional amines, where between one and all the     active hydrogen atoms on the amine are replaced, such as with     ethylenediamine, diethylenetriamine, triethylenetetramine,     hexamethylenediamine, 1,2-bis-(3-aminopropylamino)ethane, reaction     products of     2-chloro-4,6-di-(4-n-butylamino-1,2,2,6,6-pentamethylpiperidyl)-1,3,5-triazine     and     4-(4-n-butylamino-2,2,6,6-tetramethylpiperidyl)-2,6-dichloro-1,3,5-s-triazine     with mono- or polyfunctional amines, where between one and all the     active hydrogen atoms on the amine are replaced, such as with     ethylenediamine, diethylenetriamine, triethylenetetramine,     hexamethylenediamine, 1,2-bis-(3-aminopropylamino)ethane, the     condensate of 1,2-bis(3-aminopropylamino)ethane and     2,4,6-trichloro-1,3,5-triazine and also     4-butylamino-2,2,6,6-tetramethylpiperidine,     N-(2,2,6,6-tetramethyl-4-piperidyl)-n-dodecylsuccinimide,     N-(1,2,2,6,6-pentamethyl-4-piperidyl)-n-dodecylsuccinimide,     8-acetyl-3-dodecyl-7,7,9,9-tetramethyl-1,3,8-triazaspiro[4.5]decane-2,4-dione,     oligomerized     2,2,4,4-tetramethyl-20-(oxiranylmethyl)-7-oxa-3,20-diaza-dispiro[5.1.11.2]heneicosan-21-one,     oligomerized     1,2,2,4,4-pentamethyl-20-(oxiranylmethyl)-7-oxa-3,20-diazadispiro[5.1.11.2]heneicosan-21-one,     oligomerized     1-acetyl-2,2,4,4-tetramethyl-20-(oxiranylmethyl)-7-oxa-3,20-diaza-dispiro[5.1.11.2]heneicosan-21-one,     3-dodecyl-1-(2,2,6,6-tetramethyl-4-piperidyl)pyrrolidine-2,5-dione,     3-dodecyl-1-(1,2,2,6,6-pentamethyl-4-piperidyl)pyrrolidine-2,5-dione,     2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro-[5.1.11.2]-heneicosan-21-one,     2,2,4,4-tetramethyl-7-oxa-21-oxo-3,20-diazadispiro-[5.1.11.2]heneicosane-3-propanoic     acid dodecyl ester,     2,2,4,4-tetramethyl-7-oxa-21-oxo-3,20-diazadispiro-[5.1.11.2]heneicosane-3-propanoic     acid tetradecyl ester,     2,2,3,4,4-pentamethyl-7-oxa-3,20-diazadispiro-[5.1.11.2]heneicosan-21-one,     2,2,3,4,4-pentamethyl-7-oxa-21-oxo-3,20-diaza-dispiro-[5.1.11.2]heneicosane-3-propanoic     acid dodecyl ester,     2,2,3,4,4-pentamethyl-7-oxa-21-oxo-3,20-diazadispiro-[5.1.11.2]-heneicosane-3-propanoic     acid tetradecyl ester,     3-acetyl-2,2,4,4-tetramethyl-7-oxa-3,20-diazadispiro-[5.1.11.2]heneicosane-21-one,     3-acetyl-2,2,4,4-tetramethyl-7-oxa-21-oxo-3,20-diaza-dispiro-[5.1.112]heneicosane-3-propanoic     acid dodecyl ester,     3-acetyl-2,2,4,4-tetramethyl-7-oxa-21-oxo-3,20-diazadispiro-[5.1.11.2]heneicosane-3-propanoic     acid tetradecyl ester,     1,1′,3,3′,5,5′-hexahydro-2,2′,4,4′,6,6′-hexaaza-2,2′,6,6′-bismethano-7,8-dioxo-4,4′-bis(1,2,2,6,6-pentamethyl-4-piperidyl)biphenyl,     poly-N,N′-bis-(2,2,6,6-tetramethyl-4-piperidyl)-1,8-diazadecylene,     adduct of 2,2,6,6-tetramethyl-4-allyloxypiperidine and     polymethylhydridosiloxane (molar mass up to 4000), adduct of     1,2,2,6,6-pentamethyl-4-allyloxypiperidine and     polymethylhydridosiloxane (molar mass up to 4000),     N,N′-diformyl-N,N′-bis(2,2,6,6-tetramethyl-4-piperidinyl)-hexamethylenediamine,     N,N′-diformyl-N,N′-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)hexamethylenediamine,     5,11-bis-(2,2,6,6-tetramethyl-4-piperidinyl)-3,5,7,9,11,13-hexaazatetra-cyclo[7.4.0.0^(2,7).1^(3,13)]tetradecane-8,14-dione,     5,11-bis(1,2,2,6,6-pentamethyl-4-piperidinyl)-3,5,7,9,11,13-hexaazatetra-cyclo[7.4.0.0^(2,7).1^(3,13)]tetrade-cane-8,14-dione,     [(4-methoxyphenyl)methylene]-propanedioic acid     bis(2,2,6,6-tetramethyl-4-piperidinyl)ester,     [(4-methoxyphenyl)-methylene]propanedioic acid     bis-(1,2,2,6,6-pentamethyl-4-piperidinyl) ester,     2,4,6-tris(N-cyclohexyl-N-[2-(3,3,4,5,5-pentamethylpiperazinon-1-yl)ethyl]amino)-1,3,5-triazine,     copolymer of styrene with methylstyrene and maleic anhydride reacted     with 4-amino-2,2,6,6-tetramethylpiperidine and octadecylamine,     copolymer of styrene with α-methyl-styrene and maleic anhydride     reacted with 4-amino-1,2,2,6,6-pentamethylpiperidine and     octadecylamine, polycarbonate with     2,2′-[(2,2,6,6-tetramethyl-4-piperidinyl)imino]bis[ethanol] as diol     component, polycarbonate comprising     2,2′-(1,2,2,6,6-pentamethyl-4-piperidinyl)imino]bis[ethanol] as diol     component, copolymer of maleic anhydride and an α-olefin up to C₃₀     reacted with 4-amino-2,2,6,6-tetramethylpiperidine, copolymer of     maleic anhydride and an α-olefin up to C₃₀ reacted with     1-acetyl-4-amino-2,2,6,6-tetramethylpiperidine, copolymer of maleic     anhydride and an α-olefin up to C₃₀ reacted with     4-amino-1,2,2,6,6-pentamethylpiperidine, and also the N-alkyl- and     N-aryl-oxy derivatives of the above-mentioned compounds with free NH     groups on the piperidine, especially α-methylbenzyloxy and alkyloxy     from C₁ to C₁₈. -   2.7 Oxalamides, for example 4,4′-dioctyloxyoxanilide,     2,2′-diethoxyanilide, 2,2′-dioctyloxy-5,5′-di-tert-butyloxanilide,     2,2′-didodecyloxy-5,5′-di-tert-butyloxanilide,     2-ethoxy-2′-ethyloxanilide,     N,N′-bis(3-dimethylaminopropyl)-oxalamide,     2-ethoxy-5-tert-butyl-2′-ethyloxanilide and its mixture with     2-ethoxy-2′-ethyl-5,4′-di-tert-butyloxanilide and mixtures of o- and     p-methoxy-disubstituted and of o- and p-ethoxy-disubstituted     oxanilides. -   2.8 2-(2-Hydroxyphenyl)-1,3,5-triazines, for example     2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,     2-(2-hydroxy-4-octyloxyphenyl)-4′,6-bis(2′,4-dimethylphenyl)-1,3,5-triazine,     2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-(2,4-dihydroxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2,4-bis(2-hydroxy-4-propyloxyphenyl)-6-(2,4-dimethylphenyl)-1,3,5-triazine,     2-(2-hydroxy-4-octyloxyphenyl)-4,6bis(4-methylphenyl)-1,3,5-triazine,     2-(2-hydroxy-4-dodecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-[2-hydroxy-4-(2-hydroxy-3-butyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-[2-hydroxy-4-(2-hydroxy-3-octyloxypropyloxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-(2-hydroxy-4-tridecyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-[4-dodecyloxy/tridecyloxy-2-hydroxypropoxy)-2-hydroxyphenyl]4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-[2-hydroxy-4-(2-hydroxy-3-dodecyloxypropoxy)phenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,     2-(2-hydroxy-4-hexyloxy)phenyl-4,6-diphenyl-1,3,5-triazine,     2-(2-hydroxy-4-methoxyphenyl)-4,6-diphenyl-1,3,5-triazine,     2,4,6-tris[2-hydroxy-4-(3-butoxy-2-hydroxypropoxy)phenyl]-1,3,5-triazine,     2-(2-hydroxyphenyl)-4-(4-methoxyphenyl)-6-phenyl-1,3,5-triazine. -   3. Metal deactivators, for example, N,N′-diphenyloxalamide,     N-salicylal-N′-salicyloyl-hydrazine, N,N′-bis(salicyloyl)hydrazine,     N,N′-bis(3,5-di-tert-butyl-4-hydroxyphenylpropionyl)hydrazine,     3-salicyloylamino-1,2,4-triazole, bis(benzylidene)oxalyl     dihydrazide, oxanilide, isophthaloyl dihydrazide, sebacoyl     bisphenylhydrazide, N,N′-diacetyladipoyl dihydrazide,     N,N′-bis(salicyloyl)oxalyl dihydrazide,     N,N′-bis(salicyloyl)thiopropionyl dihydrazide. -   4. Phosphites and phosphonites, for example triphenyl phosphite,     diphenyl alkyl phosphites, phenyl dialkyl phosphites,     tris(nonylphenyl)phosphite, trilauryl phosphite, trioctadecyl     phosphite, distearyl pentaerythritol diphosphite,     tris(2,4-di-tert-butylphenyl)phosphite, diisodecyl pentaerythritol     diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythritol     diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol     diphosphite, bisisodecyloxy pentaerythritol diphosphite,     bis(2,4-di-tert-butyl-6-methylphenyl)pentaerythritol diphosphite,     bis(2,4,6-tri-tert-butylphenyl)pentaerythritol diphosphite,     tristearyl sorbitol triphosphite, tetrakis(2,4-di-tert-butylphenyl)     4,4′-biphenylenediphosphonite,     6-isooctyloxy-2,4,8,10-tetra-tert-butyl-12H-dibenzo[d,g]-1,3,2-dioxaphosphocin,     6-fluoro-2,4,8,10-tetra-tert-butyl-12-methyl-dibenzo[d,g]-1,3,2-dioxaphosphocin,     bis(2,4-di-tert-butyl-6-methylphenyl)methyl phosphite,     bis(2,4-di-tert-butyl-6-methylphenyl)ethyl phosphite,     tris(2-tert-butyl-4-thio(2′-methyl-4′-hydroxy-5′-tert-butyl)phenyl-5-methyl)phenyl     phosphite, 2,2′,2″-nitrilo[triethyl     tris(3,3′,5,5′-tetra-tert-butyl-1,1′-biphenyl-2,2′-diyl)phosphite],     bis[2-methyl-4,6-bis(1,1-dimethylethyl)phenol]phosphorous acid ethyl     ester. -   5. Hydroxylamines, examples being N,N-dibenzylhydroxylamine,     N,N-diethylhydroxylamine, N,N-dioctylhydroxylamine,     N,N-dilaurylhydroxylamine, N,N-ditetradecylhydroxylamine,     N,N-dihexadecylhydroxylamine, N,N-dioctadecylhydroxylamine,     N-hexadecyl-N-octadecylhydroxylamine,     N-heptadecyl-N-octadecylhydroxylamine, N,N-dialkylhydroxylamines     prepared from hydrogenated tallow fatty amine. -   6. Nitrones, examples being N-benzyl alpha-phenyl nitrone, N-ethyl     alpha-methyl nitrone, N-octyl alpha-heptyl nitrone, N-lauryl     alpha-undecyl nitrone, N-tetradecyl alpha-tridecyl nitrone,     N-hexadecyl alpha-pentadecyl nitrone, N-octadecyl alpha-heptadecyl     nitrone, N-hexadecyl alpha-heptadecyl nitrone, N-octadecyl     alpha-pentadecyl nitrone, N-heptadecyl alpha-heptadecyl nitrone,     N-octadecyl alpha-hexadecyl nitrone, nitrones derived from     N,N-dialkylhydroxylamines prepared from hydrogenated tallow fatty     amines. -   7. Zeolites and hydrotalcites, such as ®DHT 4A. Hydrotalcites of     this kind can be described by the formula     [(M²⁺)_(1-x) (M³⁺)_(x) (OH)₂ (A^(n−))_(x/n) yH₂O], -    where     -   (M²⁺) is Mg, Ca, Sr, Ba, Zn, Pb, Sn, Ni     -   (M³⁺) is Al, B, Bi     -   A_(n) is an anion of valency n     -   n is an integer from 1-4     -   x is a value between 0 and 0.5     -   y is a value between 0 and 2     -   A is OH⁻, Cl⁻, Br⁻, I⁻, ClO₄—, CH₃COO⁻, C₆H₅COO⁻, CO₃ ²⁻, SO₄         ²⁻, (OOC—COO)²⁻, (CHOHCOO)₂ ²⁻, (CHOH)₄CH₂OHCOO⁻, C₂H₄(COO)₂ ²⁻,         (CH₂COO)₂ ²⁻, CH₃CHOHCOO⁻, SiO₃ ²⁻, SiO₄ ⁴⁻, Fe(CN)₆ ³⁻, Fe(CN)₆         ⁴⁻, BO₃ ³⁻, PO₃ ³⁻, HPO₄ ²⁻.     -   Preference is given to employing hydrotalcites in which (M²⁺) is         (Ca²⁺), (Mg²⁺) or a mixture of (Mg²⁺) and (Zn²⁺); (A^(n−)) is         CO₃ ²⁻, BO₃ ³⁻, PO₃ ³⁻; x has a value from 0 to 0.5 and y has a         value from 0 to 2. It is also possible to employ hydrotalcites         that can be described with the formula         [(M²⁺)_(x) (Al³⁺)₂ (OH)_(2x+6nz) (A^(n−))₂ yH₂O].     -   Here, (M²⁺) is Mg²⁺, Zn²⁺, but more preferably Mg²⁺. (A^(n−)) is         an anion, in particular from the group consisting of Co₃ ²⁻,         (OOC—COO)²⁻, OH⁻ and S²⁻, where n describes the valency of the         ion. y is a positive number, more preferably between 0 and 5,         especially between 0.5 and 5. x and z have positive values,         which in the case of x are preferably between 2 and 6 and in the         case of z should be less than -   2. The hydrotalcites of the following formulae are to be regarded     with particular preference:     Al₂O₃×6MgO×CO₂×12H₂O,     Mg_(4.5)Al₂(OH)₁₃×CO₃×3.5H₂O,     4MgO×Al₂O₃×CO₂×9H₂O,     4MgO×Al₂O₃×CO₂×6H₂O,     ZnO×3MgO×Al₂O₃×CO₂×8-9H₂O,     ZnO×3MgO×Al₂O₃×CO₂×5-6H₂O,     Mg_(4.5)Al₂(OH)₁₃×CO₃.     -   Hydrotalcites are employed in the polymer preferably in a         concentration of from 0.01 to 5% by weight, in particular from         0.2 to 3% by weight, based on the overall polymer formulation. -   8. Thiosynergists, examples being dilauryl thiodipropionate and     distearyl thiodipropionate. -   9. Peroxide scavengers, examples being esters of β-thiodipropionic     acid, for example the lauryl, stearyl, myristyl or tridecyl ester,     mecaptobenzimidazole, the zinc salt of 2-mercaptobenzimidazole, zinc     alkyldithiocarbamates, zinc dibutyldithiocarbamate, dioctadecyl     monosulfide, dioctadecyl disulfide, pentaerythritol     tetrakis(β-dodecylmercapto)propionate. -   10. Polyamide stabilizers, examples being copper salts in     combination with iodides and/or phosphorus compounds and salts of     divalent manganese. -   11. Basic costabilizers, examples being melamine,     polyvinylpyrrolidone, dicyandi-amide, triallyl cyanurate, urea     derivatives, hydrazine derivatives, amines, polyamines,     polyurethanes, alkali metal and alkaline earth metal salts of higher     fatty acids, for example Ca stearate, Zn stearate, Mg behenate, Mg     stearate, Na ricinoleate, K palmitate, antimony pyrocatecholate or     tin pyrocatecholate, alkali metal and alkaline earth metal salts and     also the zinc salt or the aluminum salt of lactic acid. -   12. Nucleating agents, such as inorganic substances, examples being     talc, metal oxides, such as titanium oxide or magnesium oxide,     phosphates, carbonates or sulfates of, preferably, alkaline earth     metals, organic compounds, such as mono- or polycarboxylic acids and     also their salts, examples being 4-tert-butylbenzoic acid, adipic     acid; diphenylacetic acid; sodium succinate or sodium benzoate;     acetals of aromatic aldehydes and polyfunctional alcohols such as     sorbitol, for example, such as 1,3-2,4-di(benzylidene)-D-sorbitol,     1,3-2,4-di(4-tolylidene)-D-sorbitol,     1,3-2,4-di(4-ethylbenzylidene)-D-sorbitol, polymeric compounds, such     as ionic copolymers (ionomers), for example. -   13. Fillers and reinforcing agents, examples being calcium     carbonate, silicates, glass fibers, asbestos, talc, kaolin, mica,     barium sulfate, metal oxides and metal hydroxides, carbon black,     graphite, wood flour and other flours or fibers of other natural     products, synthetic fibers. -   14. Other additives, examples being plasticizers, lubricants,     emulsifiers, pigments, Theological additives, catalysts, leveling     assistants, optical brighteners, flame-proofing agents, antistatics,     blowing agents. -   15. Benzofuranones and indolines, as described for example in U.S.     Pat. Nos. 4,325,863, 4,338,244, 5,175,312; 5,216,052; 5,252,643,     DE-A4316611, DE-A-4316622, DE-A4316876, EP-A-0589839 or     EP-A-0591102, or     3-[4-(2-acetoxy-ethoxy)phenyl]-5,7-di-tert-butylbenzofuran-2-one,     5,7-di-tert-butyl-3-[4-(2-stearoyloxyethoxy)phenyl]-benzofuranon-2-one,     3,3′-bis[5,7-di-tert-butyl-3-(4-[2-hydroxyethoxy]phenyl)-benzofuran-2-one,     5,7-di-tert-butyl-3-(4-ethoxyphenyl)benzofuran-2-one,     3-(4-acetoxy-3,5-dimethylphenyl)-5,7-di-tert-butylbenzofuran-2-one,     3-(3,5-diethyl-4-pivaloyloxyphenyl)-5,7-di-tert-butylbenzofuran-2-one.

If employed in pigmented polyolefin-articles which are used under water extractive conditions after or in connection with hot water storage those mixtures show superior long term performance without significant loss of color strength. The polyolefin resin can be applied also as coated or laminated layer on metal articles such as steel-pipes or sea-cables.

The described stabilizer systems used to stabilize pigmented polyolefin-articles which are exposed to water-extracting conditions especially during or after hot water treatment are able to prevent an early consumption by migration out of the polymer resin. This behavior improves clearly the long term stability of the referred articles.

Under the consideration of the state-of-the-art for stabilizing pigmented polyolefin-articles which are exposed to water extracting conditions such a clear improvement and contribution of particular stabilizers was not expected.

The following examples shall illustrate the invention. In the following “part(s)” or “%” mean “part(s) by weight” or “% by weight”.

EXAMPLES

Preparation and Testing of Samples

Preparation of Powdered Mixtures of Polyethylene-HD with Stabilizers

In a flask 100 parts of the polyethylene-HD (type PE-HD CRP 100, unpigmented, bimodal molecular weight distribution, producer: Elenac GmbH, Frankfurt) have been mixed with the base stabilizer composition consisting of 0.1 part Ca-stearate, 0.1 part of tris(2,4-di-tert.butylphenyl)phosphite and 0.1 part of a phenolic component (either AO 1 or AO 2 or a 1:1 mixture out of these phenols). Further added are 0.2 part or 0.3 part of lightstabilizers based on LS 1 or of UV-absorbers like UV 1 or UV 2.

By using blue-pigmented test specimen, additionally 2 parts of a masterbatch called Remafin-Blue 154 containing 4.1% Pigment Blue and 2.8% TiO₂ (rutile-type) has been added.

The additives have been dissolved in acetone in the presence of the polymer and the solvent has been afterwards evaporated in the vacuum.

Homogenization was carried out using a single screw extruder (type Brabender, screw-diameter 16 mm, L/D=20) at T=210-240° C./125 rpm. By addition of the pigment-masterbatch another threefold extrusion under the same conditions took place.

The manufacture of the test-samples was carried out by punching objects from pressed plaques (300×300 mm, thickness 1 mm) which itself have been produced using a steam-heated/water-cooled hydraulic press at T=185° C.; contact pressure 30 bar for 5 min.; final pressure 200 bar for 3 min.

Teat Procedure

Hot water storage of the samples was carried out for 2 months at T=90° C. Afterwards the parameter b*₀ as defined in the CIELAB-system has been measured using a spectrophotometer type Minolta CM 3500d. In a next step the samples have been stored in a circulating air oven at a temperature of 120° C. In weekly intervals samples of individual formulations have been taken out to measure their actual b*-value. Results for b* after 0 and 5 weeks storage time in the oven are shown in table 1.

The b*-value is the so called Yellowness Index (YI) and delta b* therefore is a measure for the yellowing of the sample. TABLE 1 Effect of combined water storage (90° C./2 months) and ovenaging (120° C./5 weeks) of blue pigmented, differently stabilized PE-HD samples (thickness 1 mm); pigment: 2.0% Remafin-blue; base stabilization: 0.1% tris(2,4-di-tert.butylphenyl)phosphite, 0.1% Ca-stearate. YI = Yellowness Index Exp. Formulation b*₀ b*_(5 weeks) delta b* Comparative Examples 1 unstabilized (Reference1) −1.6 −17.4 −15.8 2 0.1% AO 1 −35.7 −33.4 2.3 3 0.1% AO 2 −17.5 sample destroyed 4 0.2% LS 1, 0.1% AO 1 −36.1 −32.6 3.5 5 0.3% LS 1, 0.1% AO 1 −35.8 −32.9 2.9 6 0.2% LS 1, 0.1% AO 1, 0.1% UV 1 −36.5 −33.1 2.5 7 0.2% LS 1, 0.1% AO 1, 0.1% UV 2 −35.4 −32.4 3 8 0.2% LS 1, 0.1% AO 2, 0.1% UV 1 −17.3 −21.8 −4.5 9 0.2% LS 1, 0.1% AO 2, 0.1% UV 2 −15.4 −22 −6.6 Examples of the Invention 10 0.2% LS 1, 0.05% AO 1, −29 −27.8 1.2 0.05% AO 2 11 0.3% LS 1, 0.05% AO 1, −29.9 −27.3 2.6 0.05% AO 2 12 0.2% LS 1, 0.05% AO 1, −30.6 −28.6 2 0.05% AO 2, 0.1% UV 1 13 0.2% LS 1, 0.05% AO 1, −27.7 −27.5 0.2 0.05% AO 2, 0.1% UV 2

The experimental data clearly show the surprisingly superior stabilizing properties of the instant stabilizer compositions compared to the prior art. 

1. A stabilizer composition for pigmented polyolefins comprising a) at least one sterically hindered amine, one of which must be the polymer of epichlorohydrin and 2,2,4,4-tetramethyl-7-oxa-3, 20-diaza-20-(2,3-epoxi-propyl)-dispiro-[5.1.11.2]-heneicosane-21-one (LS 1). and b) at least the phenolic antioxidants bis-[3,3-bis-(4′-hydroxy-3′-tert.butylphenyl)-butanoic acid]-glycolester (AO 1) and tetrakismethylene(3,5-di-tert.butyl-4-hydroxyphenyl)-hydrocinnamate (AO 2) wherein the overall weight ratio of component(s) a) to the overall weight ratio of component(s) b) is from 10:1 to 1:5.
 2. A stabilizer composition as claimed in claim 2, wherein component b) is a mixture of compound (AO 1) and (AO 2) in a weight ratio of 2:1 to 1:2.
 3. A stabilizer composition as claimed in any of claims 1 to 2, wherein an additional UV-absorber as component c) is methanone, [2-hydroxy-4-(octyloxy)phenyl]-phenyl (UV 1) or phenol, 2-(5-chloro-2H-benzotriazol-2-yl)-6-(1,1-dimethylethyl)-4-methyl (UV 2) or a 2-hydroxybenzophenone, a 2-(2-hydroxyphenyl)-benzotriazole, a 2-(2-hydroxy-phenyl)-1,3,5-benzotriazine, an oxanilide, a cinnamate or a salicylate, and wherein the weight ratio of component(s) a):component(s) b):component(s) c) is from 5:1:1 to 1:5:5.
 4. A method of use of a stabilizer composition as claimed in any of claims 1 to 3 wherein an amount of 0.001 to 2.000% by weight, based on the polymer, is incorporated into a pigmented polyolefin.
 5. A method of use of a stabilizer composition as claimed in any of claims 1 to 3 wherein an amount of 0.020 to 0.20% by weight, based on the polymer, is incorporated into a pigmented polyolefin.
 6. A method of use as claimed in claim 4 or 5 wherein the polyolefin is polyethylene.
 7. A process of stabilizing pigmented polyolefins for long term contact with water comprising incorporating therein before or during processing a stabilizing quantity of the stabilizer composition according to any of claims 1 to
 3. 8. A process according to claim 7 wherein the stabilizer composition is added in an amount of 0.001 to 2.000% by weight, based on the weight of the polymer.
 9. A process according to claim 8 wherein the stabilizer composition is added in an amount of 0.020 to 0.20% by weight, based on the weight of the polymer.
 6. The pigmented polyolefin as claimed in claim 4 wherein the polyolefin is polyethylene.
 7. A process of stabilizing a pigmented polyolefin for long term contact with water comprising the step of incorporating into the polyolefin before or during processing a stabilizing quantity of the stabilizer composition according to claim
 1. 10. The pigmented polyolefin as claimed in claim 5, wherein the polyolefin is polyethylene. 